The UAB Multidisciplinary Clinical Research Center (MCRC) is a multidisciplinary program uniquely positioned to promote research related to the causes, diagnoses, treatments and improved care of patients with arthritis and musculoskeletal diseases. The MCRC builds on the capabilities of the UAB Arthritis and vlusculoskeletal Center and its thematic workgroups (Neurobehavioral Medicine; Prevention, Outcomes, and Rehabilitation; Experimental Therapeutics; Genetics and Functional Genomics; Immunology and Autoimmunity; Bone, Cartilage and Connective Tissue). Centered on an outstanding Methodology Core comprised of faculty in biostatistics (Redden, Howard), statistical genetics (Beasley, Liu, Tiwari) and outcomes/health services research (Kiefe, Pisu, Wray), all with a proven record of collaboration in clinical investigation in musculoskeletal diseases, this MCRC proposal includes four additional supporting cores and four innovative projects: No. 1, Genetic and Molecular Markers of Methotrexate Efficacy and Toxicity in Early RA (Arnett); No, 2, Ethnic Disparities in Total Joint Arthroplasty: Pain and Stress-Related Mediators (Bradley); No. 3, Predictors of Rheumatoid Arthritis (RA) Severity in African Americans (Bridges); and No. 4, Improving Care and Refining Epidemiology in Osteoporosis (Saag). The Administrative Unit of the MCRC coordinates MCRC activities while setting the strategic agenda, facilitating interactions and collaborations, promoting scientific development, and performing continuous evaluation of ongoing MCRC programs. To assist the Center Director in his effort to ensure the highest quality in the operation of the UAB-MCRC, five committees have been established: the UAB-MCRC Executive Committee, the Scientific Cores Advisory Committee, the Data Safety and Monitoring Board, the Internal Research Advisory Committee, and the External Research Advisory Committee. These advisory groups will assist the Center Director in maximizing the strengths of the MCRC's projects, as well as in identifying and correcting any weaknesses. The Scientific Development Program, which promotes the introduction and development of new techniques and nurtures young and new faculty in musculoskeletal disease research, ensures the continued energy and vitality of this MCRC.